Batch migration of servers - Server Migration Center - Alibaba Cloud Documentation Center

You can create a workgroup to manage the lifecycles of multiple migration tasks at a time. This allows for batch migration through workgroups, enhancing the efficiency of server migration. This topic mainly introduces how to migrate servers in batch through workgroups.

Migration scenarios

Currently, batch migration through workgroups only supports migrating servers to ECS Image. After the migration is complete, you need to manually create ECS instances by using the generated ECS custom images.

Migrate a server to an ECS instance.
Migrate data between ECS instances that belong to the same Alibaba Cloud account or different Alibaba Cloud accounts.
Migrate data from a simple application server to an ECS instance.

For more information about migration scenarios, see Server migration operations.

Prerequisites

Preparations for server migration are complete. For more information, see Before you begin.
The migration template is set up. For more information, see Configure the migration template.

Procedure

Step 1: Import migration sources

Migration sources can be servers in data centers, virtual machines, hosts on other cloud platforms, or servers of other types. Depending on the following specific migration scenarios, you can import migration sources for the servers that need to be migrated:

Migrate a server to an ECS instance. For more information, see Step 1: Import Migration Sources.
Migrate data between ECS instances that belong to the same Alibaba Cloud account or different Alibaba Cloud accounts. For more information, see Step 1: Import Migration Sources.
Migrate data from a simple application server to an ECS instance. For more information, see Step 1: Import Migration Sources.

Step 2: Create a workgroup

50 workgroups can be created in each Alibaba Cloud account.

Log on to the SMC console.
In the left navigation bar, select Application Migration > Workgroup Migration.
On the Workgroup Migration page, click createWorkgroup.

In the pop-up createWorkgroup dialog box, configure parameters based on the following table.

Parameter	Description
workgroupName	Enter the workgroup name. The name must be 2 to 64 characters in length. It must start with a letter and cannot start with `http://` or `https://`. It can contain digits, colons (:), periods (.), underscores (_), and hyphens (-).
workgroupDescription	Enter the workgroup description.
Select Migration Source	Select migration sources from the drop-down list. Alternatively, you can create a workgroup, and click association in the Actions column of the corresponding workgroup to associate more migration sources. If you have not imported migration sources, you can click Import Migration Source. For more information, see Step 1: Import Migration Sources. Note A workgroup can associate up to 50 migration sources. A migration source can only be associated with one workgroup.

Click Create.
If you no longer need the workgroup later, you need to disassociate the migration sources in the workgroup, select > Delete Workgroup in the Actions column of the corresponding workgroup, and delete the workgroup as prompted.

Step 3: Start migration

In the Actions column of the target workgroup, click Start Migration.
In the Start Migration dialog box, confirm that the servers to be migrated are correct, and click Next.
If servers still exist in the Inoperable Migration Sources tab, you can click the icon to view the reasons why they cannot be migrated.
Configure the migration parameters as needed, and click Create.
If you have preset the migration task parameters in the migration template, the template parameters will be automatically filled in when the migration task is created to improve migration efficiency. For more information, see Configure the migration template.
Note
If migration tasks already exist for some migration sources, no additional migration tasks will be created for these sources.
In the message that appears, read the migration notes and click Got It.
In the pop-up Migration Settings dialog box, click View Now.
On the Workgroup Migration page, view the migration status.
1. When the Migration Status changes from Not Started to In Progress, it indicates that the servers have started migrating.
  You can click the workgroup ID to view the real-time migration status of each server. If you have enabled migration drills, SMC will first perform migration drills, and then perform migration operations after the drill is passed.
  - When the Real-time Migration Status is Drill Passed, it indicates that the migration drill is successful, and the system will automatically start the migration.
  - When the Real-time Migration Status is Drill Exception, it indicates that the migration drill fails. You need to view the drill report and fix the Critical drill items, and then retry the migration drill. For more information, see Configure a migration test.
2. When the Real-time Migration Status is Synchronizing, it indicates that the server data is being migrated.
  The time required for data transmission varies based on factors such as the size of the migration source data and the network bandwidth. Wait until the migration job is complete. At this time, you can perform the following steps based on your needs:
  - Modify migration settings: In the Actions column, click Modify Migration Job to modify the task name, task description, transmission speed limit, compression rate, and Checksum verification parameters.
  - Pause the migration operation: In the Actions column, click Pause Migration Job to pause migration.
  When the migration job is in the Synchronizing state, the Speed and Time Remaining for Synchronization parameters are displayed in the Real-time Migration Status column:
  - Speed: the amount of data that is migrated per second, which indicates the transfer speed of uncompressed data. If you set the Compression Ratio parameter to a value greater than 0, the actual network transfer speed, which is the transfer speed of compressed data, is lower than the displayed speed.
  - Time Remaining for Synchronization: the remaining synchronization time calculated based on the current speed by using the following formula: Time remaining for synchronization = (Total data size - Transferred data size)/Speed.
3. When the Real-time Migration Status is Waiting, it indicates that the first full migration of the server has been completed.
  The first migration will involve a full migration of data from the source server system and generate a full ECS custom image.

Step 4: Incremental migration

After the first migration is complete, the migration status is Waiting. SMC will wait for the next frequency cycle based on Synchronization Interval that you set to automatically run incremental migration and generate a new ECS custom image.

Note

Each ECS custom image generated during incremental migration is a full image of the current state of the source server, including the incremental data at the time of migration and all previously migrated data.

Stop the services and run an incremental migration job.
Stop the services on the source server during off-peak hours, and run the incremental migration again. Perform the following operations:
1. Log on to the source server and stop the system services.
2. Perform incremental migration.
  - Automatically perform incremental migration
    SMC will automatically run incremental migration based on Synchronization Interval that you set.
  - Manually perform incremental migration
    In the Actions column of the target workgroup, click startSync, and perform incremental migration in batches as prompted.
    Note
    You can also click the workgroup ID to perform manual incremental synchronization for each server.
Complete incremental synchronization.
After the last incremental migration operation is complete, perform the following steps to complete incremental migration:
1. In the Actions column of the target workgroup, select > Complete Incremental Synchronization.
2. In the Run Incremental Job dialog box, click Next.
  You can also select Perform One Last Synchronizatio in the Complete Incremental Synchronization dialog box to complete the last data synchronization.
3. Click Next to confirm the migration sources.
4. Click OK to start incremental synchronization.
5. On the Workgroup Migration page, view the migration status.
  The amount of time required for data transmission is subject to factors such as the data size of the migration source and network bandwidth. Wait until the migration job is complete. When the migration status is Completed, the migration is successful.
Note
After you complete incremental migration, no more incremental migration operations are automatically performed and you cannot manually run the migration job. If you click Complete Incremental Synchronization and confirm the completion by accident but still need to migrate incremental data, re-create a migration job.

Verify migration results

After the migration is successful, a custom Alibaba Cloud image will be generated.
1. On the Workgroup Migration page, click the workgroup ID.
2. In the Migration Deliverables column of the target migration source, view the ECS custom image.
  At the same time, you can click View Report to view the image detection results. For more information, see Configure image check.
Verify the migration results.
(Recommended) Manually verify the migration result
1. In the Actions column of the target migration source, click Create Instance to go to the ECS instance creation page in the ECS console. The custom ECS image created after migration is selected by default.
2. Create an ECS instance using the custom image. For more information, see Create an instance by using a custom image.
Use the automatic migration result verification feature
Note
To use this feature, you must install the Cloud Assistant Agent in your instance, and the system version of the instance must support this feature. For more information, see Install Cloud Assistant Agent.
This feature verifies whether the image generated by the migration job can be used to create and start instances. This verification is based on the CloudOps Orchestration Service (OOS) template named ACS-SMC-CreateAndVerifyInstance provided by Alibaba Cloud.
1. In the Actions column of the target migration source, click Verify Migration Result.
2. In the dialog box that appears, read the instructions on the verification process and click Verify Now.
  You can also click Customize Verification Parameters to configure the parameters.
3. In the Verify Migration Result column, view the verification result. Valid values:
  - Verified: Indicates that the migration is successful. You can click View Output Parameters to check the details.
  - Not Verified: Indicates that the migration failed. You can click View Cause to view the cause of errors and troubleshoot issues.
  You can also click in the Actions column, and select View Verification Records in OOS Console to view the template history.

After the server is migrated, you must perform the following operations to ensure normal operation of your business:

Verify the integrity and correctness of the data. For more information, see the How do I check my system after I migrate a Linux server? or How do I check my system after I migrate a Windows server? section of the "FAQ" topic.
Manually start the applications and services after the migration if automatic start is not enabled for the applications and services on the source server.
The IP address changes after the migration job is complete. Change the IP address of the server after the migration if your business involves IP address configuration.
- If a domain name has been bound to the source server, the public IP address of the server is changed after the migration. In this case, you must resolve the domain name to the new public IP address of the server. For more information, see Add an A record for a website domain name.
- If you want to keep the private IP address unchanged, you can modify the private IP address after the migration is complete. For more information, see Modify the private IP address of an instance.

Clear resources

During migration, SMC will create a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance under your Alibaba Cloud account to assist with migration. The method to clear resources depends on whether the migration is successful.

If the migration is successful, the intermediate instance is automatically released. No manual operation is required.
If the migration fails, the intermediate instance is not automatically released and incurs fees as long as the migration job exists. You can release the intermediate instance in one of the following ways to reduce costs:
- If you confirms that you no longer need the migration task, click the workgroup ID, click the migration source ID, and click Clear Migration Job in the Actions column of the migration task to automatically clear the intermediate instance.
- Manually release the intermediate instance. For more information, see Release an instance.

References

If you need to migrate a single server, see: